From the state of the art, centering devices of drawer slides inside cabinet walls are well known, which utilize for this purpose one of several different complicated mechanisms, as for example, inserted symmetrical folding shears or spring elements on both longitudinal sides of the drawer slides.
The disadvantage of this state-of-the-art centering mechanism is the fact that the whole lateral force, that works when, for example, the drawer is pushed in, must be transferred by the complicated mechanism and is, thus, exposed to increased wear. Besides, this centering mechanism is expensive to produce and maintain. Also, the centering only functions with parallel cabinet sides.
Document DE 299 23 509 U1 makes known a pull-out slide for a pull-out insert/drawer in a cabinet, including a cabinet-side and an insert-side slide rail for both sides of the insert; whereby, between each of the vertical side walls of the insert and the insert-side drawer slide is an elastic springy/flexible equalization element, so that the insert is centered in the center of the cabinet body crosswise to the insert direction. The equalization element can be designed as a spiral spring, leaf spring, compound spring or plate spring.
The disadvantage of this design is that the centering mechanism for the drawer is located between the drawer and the insert-side slide rail and must, therefore, be pre-mounted. This makes the system inflexible and makes replacement of the centering mechanism difficult in case of a defect.